The present invention relates to an articulation mechanism of an arc welding robot, and more particularly to an articulation mechanism of an arc welding robot having a plurality of drive arms.
With reference to FIG. 1, which illustrates a conventional multi-articulation type arc welding robot, a swivel slide 2 is rotatably provided on the upper portion of a fixed table 1 on which a robot body is supported. A brachium section 3 is coupled to the swivel slide 2.
The brachium section 3 has a brachium 4 and links 5 and 6 coupled to the swivel slide 2. An antebrachium section 7 is coupled to one end of each of the brachium 4 and link 6 of the brachium section 3 and a welding torch 8 is supported at the tip end of the antebrachium section 7 through a plurality of wrists (not shown).
The swivel slide 2 is driven by a drive motor (not shown) incorporated into the fixed table 1 through a reduction mechanism and the welding torch 8 is driven by a drive motor 9 mounted on a side of the swivel slide 2.
In the conventional articulation mechanism of an arc welding robot just described, the mechanism is arranged such that the driving force of the motor for driving the swivel slide 2, the brachium section 3, and the respective wrists of the antebrachium section 7 is transmitted to the respective drive arms through chains, timing belts, or the like. As a result, the chains, timing belts, or the like, may be non-elastically elongated or deformed, or back-lash may be caused in the chains, the timing belts, or the like, as the robot repetitively moves with rapid acceleration/deceleration, resulting in a deterioration in the positioning accuracy of the welding torch.
In addition, although in recent years there has been a demand to develop an articulation mechanism of an arc welding robot having four wrists, for the purpose of optimizing the welding attitude, the practical application of a TIG arc welding robot, the practical application of a welding wire sensor, etc., such optimization has not been attained because the above-mentioned problem could not be solved.